Automated Logic - Scheduler Add On Usage Notes

After discovery of how the Scheduler add on actually works, we've documented some best practices when setting up your zones along with some known issues and caveats.  If you are controlling zone schedules using this Add On and E2H, it is assumed that E2H will be sending primary schedule data, not WebCtrl schedules.  Attempting to add exception schedules in WebCtrl may not have the desired affect.  

It is strongly advised that you test your zone scheduling strategy, including overrides, before applying a specific configuration to all of your zones.

Block Diagram
(rough translation)

The general diagram above shows two methods in which E2H can connect to affect zone occupancy.  The SendExceptionSchedule action pushes exception schedules to the Scheduling Add-On schedule objects to override schedules for the zone.  The StartStop action will override the zone's occupancy command Binary Value point directly, ignoring any Weekly, Holiday or exception schedules in WebCtrl.
If optimal start for the zone is needed, then the SendExceptionSchedule action should be used so that the OST logic can receive the schedules for the next 24 hours.  
The information following pertains only to the use of the SendExceptionSchedule action and the ALC Scheduling Add-On.

Scheduling Add-On Best Practices

  1. Check the "Ignores Schedules Above" in WebCtrl so only the zone schedules are considered and not anything above it (e.g. building schedules).  This should eliminate weekly schedules from the zone so these schedules can't occupy the zone in periods when E2H schedules are off.
  2. It apparently doesn't matter what event priority E2H uses to send its schedules.  All exceptions sent by E2H are converted to WebCtrl override exception schedules.
  3. If you don't want a weekly schedule running while E2H is scheduling, then make sure "Initialize Midnight" is checked and the Stop Value = Unoccupied CMD value  (Not NULL).  This will effectively override the entire day with the exception schedule.  If nothing is scheduled in E2H, the zone will be overridden OFF.
  4. Check "Overwrite All Exception Schedules".  This will ensure that any exceptions that are read back from WebCtrl are removed before E2H writes back the schedules.  The schedules coming back from WebCtrl are NOT BACnet compliant (priorities are reversed) and should not be sent back to WebCtrl as overrides.  Even if you uncheck this option, DO NOT rely on a WebCtrl override schedule to be preserved because it will not override as expected.  If you want to ensure an operator override of the zone, override the zone occupancy point instead.
  5. If you want E2H to override unoccupied periods like Holidays in WebCtrl, you must enable the WebCtrl option for the zone to enable overrides.  See the "Allow Exception-Schedules to write Unoccupied periods" in the options page in WebCtrl.
  6. When a "Verify" is used to read current schedule data from BACnet, Exceptions returned may not accurately represent actual schedules and priorities in the WebCtrl zone.  View the zone's WebCtrl schedule to see what the actual schedules are.

Use of NULL vs OFF Values

If you want your zone to be able to use other WebCtrl schedules after the E2H override event is over, you can specify "Reliquish CMD" or NULL to be sent at the end of the exception schedule.  Otherwise, the OFF cmd value will remain as on override command in WebCtrl until the rest of the day. 
To prevent weekly schedules, holidays, or other WebCtrl schedules from occupying a zone prior to the first Occupied command sent from E2H, initialize the start of the day with an Unoccupied by checking the option "Initialize Midnight" in E2H.  This will ensure an Occupied or Unoccupied command will be issue at the start of the day so nothing else can command the zone.  Also make sure you have the option "Allow Exception-Schedules to write Unoccupied periods" checked in webCtrl.
If you command OFF values (instead of NULL), make sure you allow unoccupied periods to be commanded in "Allow Exception-Schedules to write Unoccupied periods" in the options page in WebCtrl.

Reverting to Default Schedules

In the event of a disruption to the E2H server or its schedules, there is not a way (that we know of) where default schedules for the zone can be automatically switch over for zone control.  Even though E2H has a status BV point to allow for an automatic switchover, the operator would have to manually remove all the exception schedules for the zone and allow a weekly or WebCtrl exception schedule to take over (uncheck "Ignore schedules above" in WebCtrl).

v1.0 Known Issues

  • After a controller is downloaded, the Add On schedules don't get restored after the download.  This can cause the zone to be unoccupied until Events2HVAC sends another schedule push, which is determined by any changes to event schedules within the 24 hr event window.  To force schedules in E2H, you would need to open the action for that zone and "Send Test Schedules".
  • When viewing the exception schedules in the Add On schedule objects, the exceptions are translated/transformed from the internal zone schedules and the priorities shown (1=lowest, 16=highest) are in reverse from what the BACnet specification calls for (1=highest, 16=lowest).  This can be very confusing to the E2H users looking at the current exception data for the zone.  Moreover, WebCtrl doesn't assign static priorities for each type, but instead they recalculate the schedules and assign the lowest priority group = 1, then incrementally add 1 for other higher priority schedules like Holiday and Override schedules.  So if all 3 types are present, 1=lowest (normal), 2=Holiday, 3=highest (Override) and they will look like this below in E2H.

Events2HVAC Help References
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